Rotor for gas turbines and rotary compressors



G. JENDRAsslK lFiled Juiy 5, 193s -I-Ugv..

Boron Fon @As TURBINES .mn ROTARY `cownmzssoxzs Sept 3, 1940 G. JENDRAssLK KOTOR FUR'GAS TURBIN-ES AND ROTARY COMPRESSURS 2 Sheets-Sheet 2 Filed July 5, 1958 Invenor'.-

Patented Sept. 3, '1940 UNITED STATES ROTOR FOR GAS TURBINES AND ROTARY" COMPRESSORS l f George Jendrassik, Budapest, Hungary Application July 5, 1938, Serial No, 217,504 In Hungary July 7, 1937 7 Claims.

In the case of rotors rotating at high peripheral speeds, such as are employed in gas orsteam turbines or compressors and which in general carry turbine blades or compressor blades, re-

6 spectively, itis, in View of the substantial effects of centrifugal force, necessary to attach the various blade rings to members constructed in the form of discs. It likewise, in consequence of the high peripheral velocity i. e. the high number of revolutions per minute, is necessary to ensure that the Working speed of the rotor should remain below its critical number of revolutions per minute, particularly if it is desired to make the clearances between the blade tips of the machines and the casing or the rotor, respectively, of small magnitude.

The arrangements as known up to now have not b'een suitable for the safe centering of the discs relatively to each other and for assuring a i550 suitable amount of rigidity to the rotor in case the high critical speed mentioned should be attained.

The rotor according to the invention, composed by the assembly of anumber of parts is, on the one hand, representing an arrangement which-as it consists of a number of discsoifers substantial resistance against centrifugal forces, whilst on the other hand it also possesses n the necessary degree of rigidity. si@ In order to enable these advantages to be obtained, supporting members are provided in the rotor according to the invention between discs pressed one against the other in the axial direction, the parts of the `said supporting members 35 supported on the'discs possessing the shape of cylindrical and conical surfaces or of double conical surfaces the generatrices of which are sloping in different directions relatively to each other in the-axial section, and are supported on the discs on centering rings or other centering memf bers, such centering rings or other centering members being employed on a circle of smaller and on a circle of larger diameter on each disc. I The supporting members may themselves also be united with the discs, and no matter whether they are thus united or whether they represent independent parts, they will be propped on the same radius on the opposite sides of the disc, 50 and in addition hereto, in case they are also united with discs (in such a manner that each supporting member is made integral `with one disc) these united parts are also joined on to each other on the same radius and accordingly 55 transmit the compression forces in each case (ci. sog-41) without any bending moments being exerted on the discs.

In order to enable the invention to be more readily understood, Fig. 1 represents the diagrammatical cross-section of a gas turbine rep- 5 resenting an embodiment of the invention shown by way of example. Fig. 2 is the diagrammatical cross-sectional view drawn to a larger scale of the discs and of the supporting members, Fig. 3 is the longitudinal section of a gas turbine composed of a compressor, of a combustion chamber and of a turbine in which a rotor accordingto the invention is employed, whilst Figs. 4 and 5 represent diagrammatical cross-sectional Views of two other variants of construction of the supporting members. I

On Fig. 1 the rotor assembled of a plurality of the discs 2, 2 alternating with each other in the axial direction and xed on the shaft 1 supportedin the bearings 5 and 6 is arranged in the turbine casing l. The rotary blades 8 are fixed on the discs whilst the stationary blades 9 are accommodated in the casing I. In the embodiment shown by Way of example the discs 2, 2 carrying the rotary blades are compressed against each other by means of the nut l0 capable of being tightened'on the shaft 'l passing through the central bores of the said discs. In order to stay the discs relatively to each other there are arranged between them, in thevpresent form of construction shown by way of example', supporting members Il, Il each of which is made integral with one of the discs 2, the said 'supporting members being-at least on those of their ends by which they are supported against the adjacent discsof double truncated cone shape. These supporting members are, with ,their supporting ends, supported on the adjacent discs 2 between the external centering surface l2 and the internal centering surface I3 40 of the latter, so that the supporting member of double cone shape will be supported against radially centering rings or centering members on one smaller and one greater radius in thev oase of each supporting member. The greater the 45 compression in the axial direction exerted on the discs by means of the supporting members the more perfectly will the supporting members become pressed radially` also ,against the centering surfaces 'so that the unavoidable inaccuracies of manufacture, A which in the case of rotors of high peripheralspeed are-even if they amount only to hundredths of millimetres-very disadvantageous, 'can in 'this manner becompletely eliminated, because a deformation in a small ex- 55 tent of the supporting member of double cone shape will balance them. In the case of this example of construction the axial ,compression force ofthe nut I Il is being transmitted to the vdiscs situated at the rotor ends by means of the tapered end supports I4 and I5. In View of the fact that it is not permissible that the force compressing the discs should also have to overcome the uncertain amount of friction between the disc hubs and the shaft I, it is in general not possible to fit the shaft 1 closely into the discs. In case the discs have to transmit a torque of such magnitude which can no longer be left to friction between the discs and the supporting members, it will be advisable to provide, moreover, for the purpose of the transmission of the torque, mutually engaging tooth systems onthe supporting members and on the discs. In Figs. 1 and 2 there is provided on one. of the supporting cones II or II' respectively,-in the example shown, on the inner cone--the tooth system 3 which engages with the tooth system 4 arranged on the disc 2. Thus the torque absorbed will pass from one disc to the other disc by means of a mechanical connection without making use of friction, whilst with the aid of the tooth system provided on the tapered end support I5 keyed on the shaft 1, it will become transmitted to the rotating shaft. Either the internal or the external part ,of the double cone surfaces of the supporting members may also be made of cylindrical shape; although this arrangement is not so rigid as the one in which both surfaces are' cone-shaped, it can nevertheless also be employed with satisfactory results.

The double supporting members arranged between the discs may, starting from the bearings of the rotor, preferably pass to greater and greater radii, so as to result in a structure similar to an equi-resistant form, which in crosssection resembles a lattice girder. This type of design will-as explained-ensure excellent centering, and in addition hereto will impart complete rigidity to the discs arranged one beside the other either against their being bent relatively to each other, or also against their being axially displaced parallel to themselves, and at the same time it is a structure of very light weight.

If the rotor according to the invention is employed not in connection with a. steam turbine, but in connection with a gas turbine, where the temperature of the gases is very high, the internal cooling of the rotor may become necessary. In this case the bore-holes I6, I1, I8, I9 shown on Fig. 1 are provided on the discs as well .as on the staying members, the said bore holes being suitable for permitting the passage of the cooling medium circulating bL .ween the discs. The cooling medium'fiows along the path indicated by the arrows traced on the drawings. It is preferable in such a'case to close the working space of the gas turbine -against the space of the cooling medium, as the pressure of the two mediums will be necessarily unequal. This arrangement is carried into effect on the embodiment shown by way of example on the drawings in such a manner that a flange 20 is provided on the periphery of each disc, which is; supported against -the ring 2| situated opposite to it on the adjacent disc and which thus closes the two spaces mentioned against each other. Centrifugal force also will contribute to assuring mutual contact in a manner excluding leakage between the flange 2l) and l the ring 2 I.

In the case of the embodiment shown on Fig. 3 one group of the discs of the rotor rotating around the axis 22, which group comprises the discs situated between the discs 23 and 24, carries blades 25 functioning as compressor blades. On the other hand, the other group-situated between the discs 26 and 2'I-of the discs of the rotor carries blades 29 functioning as turbine blades. yThe combustion space 30 may be arranged between the compressor and the turbine. In the case of this type of design, accordingly, the compressor rotor and the turbine rotor/ are built integral, whereby on the one hand any journalling between the'two units of machinery mentioned becomes unnecessary, whilst on the other hand a. rigid and lightweight type of design can be obtained. The staying member between the discs can, as is the case between the discs 24 and 26, be constructed in such a manner that the part 3| of greater or shorter length situated between the double cone shaped reposing ends of the discs should be of simple conical or cylindrical shape. In the case of this arrangement shown by Way of example `the space between the turbine discs (the space of the cooling medium) is closed against the working space o f theturbine in such a manner that an independent ring 34 is in contact in a manner excluding leakage on the flanges 32 and 33 of each two adjacent discs. This ring will be pressed by centrifugal force to the flanges and thus the centrifugal force will assist in ensuring l dius). It is also possible to construct the sup-y porting members in such a manner that only one of their cone-shaped parts is made integral with any disc, whilst the other part represents a separate piece.

0n Fig. 5 lthe supportingcones 42, 43, 44, 45 have been made integral with the disc 4I and the ends supported against the adjacent disc 46 of the cone surfaces 42, 43 are centered by means of the ring 41, which centers the cone 43 in the outward and the cone 42 in the inward direction. (On the other side of the disc 4I the same is the case with the cones 44 and 45.)

Under the effect of the axial force .compressing the ldiscs the cones will become supported still `more strongly against the centering surfaces. In general any staying cone has to b'e supported or centered in the radial direction from outside on its end of greater radius and from inside on its end of smaller radius.

vBesides the constructions shown by way of example on Fig. 1 or 3, the discs of which the rotor is composed can be pressed against each other in the axial direction by means o1' the most different members,

All these as well as other constructional arrangements which for the sake of brevity have not been mentioned in the specicatlon are also covered by the range of protection of the invention.

I claim:

1. In a rotor for turbines and rotary compressorsya plurality of discs carryingblades, supporting members between the adjacent discs having at least in the vicinity of their supporting ends the form of two diverging surfaces, and centering members, on the said discs, centering the said supporting members in the radial direction from outside and from inside, on a circle of smaller and on a circle of greater radius.

2. In a rotor for turbines and rotary compressors, a plurality of discs carrying blades, supporting members between the adjacent discs having the form of two conical surfaces and supporting the disc to be stayed on both sides on the same radii, and centering rings on the said discs centering the said supporting members in the radial direction from outside and from inside,- on a circle of smaller and on a circle of greater radius, the said members by which the discs are stayed being made, at least in part, integral with individual discs.

3. In a rotor for turbines and rotary compressors, a plurality of discs carrying blades, a peripheral iiange on the individual discs extending to one of the adjacent discs and engaging with a peripheral ring of the latter in a tight manner, supporting members between the adjacent discs having the form of two conical surfaces and supporting the disc to be stayed on both sides on the same radii, andcentering rings on the said discs centering the said supporting members in the radial direction from outside and from inside, on a circle of smaller and on a circle of greater radius, the said members by which the discs are stayed being made, at least in part, integral with individual discs.

4. In a rotor for turbines and rotary compressors, a plurality of discs carrying blades, a peripheral flange on the individual discs extending to one of the adjacent discs and engaging with a peripheral ring of the latter in a tight manner, supporting members between the adjacent discs having the form of two conical surfaces and supporting the disc to be stayed on both sides on the same radii, openings in the discs and in the supporting members for permitting the passage of a cooling medium serving for the internal cooling of the rotor, and centering rings on the said discs centering the said supporting members in the radial direction from outside and from inside, on a circle of smaller and on a circle oi' greater radius, the said member by' which the discs are stayed being made, at least in part, integral with individual discs.

5. In a rotor for turbines and rotary compressors, a plurality of discsv carrying blades, a peripheral flange on the individual discs, supporting members between the adjacent' discs having the form of two conical surfaces and supporting the discs to be stayed on both sides on the same radii, openings in the discs and in the supporting members for permitting the passage of a cooling medium serving for the internal cooling of the rotor, independent packing rings tted into the said peripheral flanges of the discs, and centering rings on the said discs centering the said supporting members in the radial direction from outside and from inside on a circle of smaller and on a circle of greater radius, the said members by which the discs are stayed vbeing made, at least in part, integral with individual discs.

6. In a rotor for turbines and rotary compressois, a plurality ci' discs carrying blades, supporting members between the adjacent discs having the form of two conical surfaces and supporting the disc to be stayed on both sides on the same radii, mutually engaging tooth systems on the discs and on the supporting members for the purpose of torque transmission, and centering rings on the said discs centering the said supporting members in the radial direction from outside and from inside, on a circle of smaller and on a circle of greater radius, the said members by which the discs are stayed being made, at least in part, integral with individual discs.

7. In a rotor for turbines and rotary compressors, a plurality of discs carrying blades, supporting members between the adjacent discs having 'at least in the vicinity of their supporting ends the form of two diverging surfaces,` means comprising a screw spindle for the threaded end of the turbine shaft pressing the discs and the supporting members against each other -in the axial direction, and centering rings on the said discs centering the said supporting members in the radial direction from outside and from inside, on, a circle of smaller and on a circle of greater radius.

GEORGE JENDRAssIK.- 

